Light emitting device and display device including the same

ABSTRACT

A light emitting device, includes: a substrate; a light emitting element on the substrate, the light emitting element having a first end portion and a second end portion arranged in a longitudinal direction; one or more partition walls disposed on the substrate, the one or more partition walls being spaced apart from the light emitting element; a first reflection electrode adjacent the first end portion of the light emitting element; a second reflection electrode adjacent the second end portion of the light emitting element; a first contact electrode connected to the first reflection electrode and the first end portion of the light emitting element; an insulating layer on the first contact electrode, the insulating layer having an opening exposing the second end portion of the light emitting element and the second reflection electrode to the outside; and a second contact electrode on the insulating layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2016-0175770, filed on Dec. 21, 2016, in the KoreanIntellectual Property Office, the entire content of which isincorporated herein by reference in its entirety.

BACKGROUND 1. Field

The present disclosure relates to a light emitting device, and a displaydevice including the same.

2. Description of the Related Art

A Light Emitting Diode (hereinafter, referred to as an “LED”) exhibitscomparatively excellent durability in under a poor environmentcondition, and has excellent performance in terms of life and luminance.Recently, research on an application of the LED to various lightemitting devices has been actively conducted.

As a part of the research, a technology for manufacturing a subminiaturerod-shaped LED, which is small in the level of micro scale or nanoscale, by using a structure, in which an inorganic crystal structure,for example, a nitride-based semiconductor, is grown, has beendeveloped. For example, the rod-shaped LED may be manufactured in asmall size with which a pixel of a self-emitting display panel and thelike may be formed.

The above information disclosed in this Background section is forenhancement of understanding of the background of the inventice concept,and therefore, it may contain information that does not constitute priorart.

SUMMARY

Aspects of some example embodiments of the present invention include alight emitting device, which is capable of improving light emissionefficiency, and a display device including the same.

According to some example embodiments of the present invention, a lightemitting device includes: a substrate; a light emitting element on thesubstrate, the light emitting element having a first end portion and asecond end portion arranged in a longitudinal direction; one or morepartition walls disposed on the substrate, the one or more partitionwalls being spaced apart from the light emitting element; a firstreflection electrode adjacent the first end portion of the lightemitting element; a second reflection electrode adjacent the second endportion of the light emitting element; a first contact electrodeconnected to the first reflection electrode and the first end portion ofthe light emitting element; an insulating layer on the first contactelectrode, the insulating layer having an opening exposing the secondend portion of the light emitting element and the second reflectionelectrode to the outside; and a second contact electrode on theinsulating layer, the second contact electrode being connected to thesecond reflection electrode and the second end portion of the lightemitting element through the opening.

According to some example embodiments, any one of the first and secondreflection electrodes is on the partition wall.

According to some example embodiments, the first and second reflectionelectrodes and the partition wall comprise different materials.

According to some example embodiments, the partition wall includes aninsulating material and the first and second reflection electrodesinclude a conductive material.

According to some example embodiments, when viewed on a plane, the firstcontact electrode overlaps the first reflection electrode, and thesecond contact electrode overlaps the second reflection electrode.

According to some example embodiments, the light emitting element is alight emitting diode shaped like a cylinder or a polyprism having amicro scale or a nano scale.

According to some example embodiments, the light emitting elementcomprises: a first conductive semiconductor layer in which a firstconductive dopant is doped; a second conductive semiconductor layer inwhich a second conductive dopant is doped; and an active layer disposedbetween the first and second conductive semiconductor layers.

According to some example embodiments, any one of the first and secondcontact electrodes includes a conductive material, of which a workfunction is less than 4.1 eV, and the other of the first and secondcontact electrodes includes a conductive material, of which a workfunction is larger than 7.5 eV.

According to some example embodiments, each of the first and secondreflection electrodes is on the partition wall.

According to some example embodiments, the light emitting device furtherincludes a support member between the substrate and the light emittingelement.

According to some example embodiments, the support member includes aninsulating material.

According to some example embodiments, the light emitting device furtherincludes an insulating film on an outer circumferential surface of thelight emitting element.

According to some example embodiments of the present invention, adisplay device includes: a substrate including a pixel area; a pixel inthe pixel area and having one or more thin film transistors; and a lightemitting device on the thin film transistor and connected to the thinfilm transistor, wherein the light emitting device comprises: aplurality of light emitting elements on the substrate, the plurality oflight emitting elements each having a first end portion and a second endportion arranged in a longitudinal direction; one or more partitionwalls spaced apart from each of the plurality of light emittingelements; a first reflection electrode adjacent the first end portion ofeach light emitting element; a second reflection electrode adjacent thesecond end portion of each light emitting element; a first contactelectrode connected to the first reflection electrode and the first endportion; an insulating layer on the first contact electrode, and havingan opening exposing the second end portion and the second reflectionelectrode to the outside; and a second contact electrode on theinsulating layer and connected to the second reflection electrode andthe second end portion through the opening, and any one of the first andsecond reflection electrodes is connected to the thin film transistor.

According to some example embodiments, any one of the first and secondreflection electrodes is on the partition wall.

According to some example embodiments, the first and second reflectionelectrodes and the partition wall include different materials.

According to some example embodiments, the partition wall includes aninsulating material and the first and second reflection electrodesinclude a conductive material.

According to some example embodiments, when viewed on a plane, the firstcontact electrode overlaps the first reflection electrode, and thesecond contact electrode overlaps the second reflection electrode.

According to some example embodiments, each of the plurality of lightemitting elements is a light emitting diode shaped like a cylinder or apolyprism having a micro scale or a nano scale.

According to some example embodiments, any one of the first and secondcontact electrodes includes a conductive material, of which a workfunction is less than 4.1 eV, and the other of the first and secondcontact electrodes includes a conductive material, of which a workfunction is larger than 7.5 eV.

According to some example embodiments, each of the first and secondreflection electrodes is on the partition wall.

According to some example embodiments of the present invention, it maybe possible to provide the light emitting device, which is capable ofimproving light emission efficiency.

Further, according to some example embodiments of the present invention,it may be possible to provide the display device including the lightemitting device.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of some example embodiments of the present invention will now bedescribed more fully hereinafter with reference to the accompanyingdrawings; however, they may be embodied in different forms and shouldnot be construed as limited to the embodiments set forth herein. Rather,these embodiments are provided so that this disclosure will be morethorough and more complete, and will more fully convey the scope of theexample embodiments to those skilled in the art.

In the drawing figures, dimensions may be exaggerated for clarity ofillustration. It will be understood that when an element is referred toas being “between” two elements, it can be the only element between thetwo elements, or one or more intervening elements may also be present.Like reference numerals refer to like elements throughout.

FIG. 1 is a perspective view illustrating a rod-shaped light emittingdiode according to some example embodiments of the present invention.

FIG. 2 is a diagram illustrating a light emitting device according tosome example embodiments of the present invention.

FIGS. 3A to 3E are circuit diagrams illustrating unit emission areas ofthe light emitting device according to some example embodiments of thepresent invention, and particularly, are circuit diagrams illustratingexamples of pixels forming a passive light emitting display panel.

FIGS. 4A to 4C are circuit diagrams illustrating unit emission areas ofthe light emitting device according to some example embodiments of thepresent invention, and particularly, are circuit diagrams illustratingexamples of pixels forming an active light emitting display panel.

FIG. 5 is a top plan view illustrating a unit emission area of the lightemitting device according to some example embodiments of the presentinvention.

FIG. 6 is a cross-sectional view taken along line I-I′ of FIG. 5.

FIGS. 7 to 14 are cross-sectional views sequentially illustrating amethod of manufacturing the light emitting device illustrated in FIG. 6.

FIG. 15 is a diagram illustrating a unit emission area of a lightemitting device according to some example embodiments of the presentinvention, and is a cross-sectional view taken along line I-I′ of FIG.5.

FIG. 16 is a diagram illustrating a unit emission area of a lightemitting device according to some example embodiments of the presentinvention, and is a cross-sectional view taken along line I-I′ of FIG.5.

FIG. 17 is a top plan view illustrating a unit emission area of a lightemitting device according to some example embodiments of the presentinvention.

FIG. 18 is a cross-sectional view taken along the line II-II′ of FIG.17.

FIGS. 19 to 27 are cross-sectional views sequentially illustrating amethod of manufacturing the light emitting device illustrated in FIG.18.

DETAILED DESCRIPTION

The present disclosure may be variously modified and have various forms,so that some example embodiments will be illustrated in the drawings anddescribed in detail in the text. However it should be understood thatthe present disclosure is not limited to the specific embodiments, butincludes all changes, equivalents, or alternatives which are included inthe spirit and technical scope of the present disclosure.

In the description of respective drawings, similar reference numeralsdesignate similar elements. In the accompanying drawings, sizes ofstructures are illustrated to be enlarged compared to actual sizes forclarity of the present disclosure. Terms “first”, “second”, and the likemay be used for describing various constituent elements, but theconstituent elements should not be limited to the terms. The terms areused only to discriminate one constituent element from anotherconstituent element. For example, a first element could be termed asecond element, and similarly, a second element could be also termed afirst element without departing from the scope of the presentdisclosure. As used herein, the singular forms are intended to includethe plural forms as well, unless the context clearly indicatesotherwise.

In the present disclosure, it should be understood that terms “include”or “have” indicates that a feature, a number, a step, an operation, acomponent, a part or the combination thoseof described in thespecification is present, but do not exclude a possibility of presenceor addition of one or more other features, numbers, steps, operations,components, parts or combinations, in advance. It will be understoodthat when an element such as a layer, film, region, or substrate isreferred to as being “on” another element, it can be directly on theother element or intervening elements may also be present. Further, inthe present disclosure, when a part of a layer, a film, an area, aplate, and the like is formed on another part, a direction, in which thepart is formed, is not limited only to an up direction, and includes alateral direction or a down direction. On the contrary, it will beunderstood that when an element such as a layer, film, region, orsubstrate is referred to as being “beneath” another element, it can bedirectly beneath the other element or intervening elements may also bepresent.

Hereinafter, a light emitting device according to some exampleembodiments of the present invention will be described with reference tothe example embodiments of the present disclosure and relevant drawings.

FIG. 1 is a perspective view illustrating a rod-shaped light emittingdiode according to some example embodiments of the present invention. InFIG. 1, a cylindrical and rod-shaped light emitting diode (LED) LD isillustrated, but the present disclosure is not limited thereto.

Referring to FIG. 1, the rod-shaped LED LD according to some exampleembodiments of the present invention may include first and secondconductive semiconductor layers 11 and 13, and an active layer 12interposed between the first and second conductive semiconductor layers11 and 13. For example, the rod-shaped LED LD may be implemented with alaminated structure, in which the first conductive semiconductor layer11, the active layer 12, and the second conductive semiconductor layer13 are sequentially laminated.

According to some example embodiments of the present invention, therod-shaped LED LD may be provided in a rod shape extended in a direction(e.g., a predetermined direction). When it is assumed that an extensiondirection of the rod-shaped LED LD is a longitudinal direction, therod-shaped LED LD may have a first end portion and a second end portionin the extension direction. In some example embodiments of the presentinvention, one of the first and second conductive semiconductor layers11 and 13 may be disposed at the first end portion, and the other of thefirst and second conductive semiconductor layers 11 and 13 may bedisposed at the second end portion.

In some example embodiments of the present invention, in FIG. 1, therod-shaped LED LD may be provided in a cylindrical shape. However, the“rod shape” may include a rod-like or bar-like shape, such as a cylinderand a polyprism, which is elongated in the longitudinal direction (thatis, an aspect ratio is larger than 1). For example, a length of therod-shaped LED LD may be larger than a diameter of the rod-shaped LEDLD.

The rod-shaped LED LD may be manufactured to be small to have a diameterand/or a length in a level of, for example, a micro scale or a nanoscale. However, the size of the rod-shaped LED LD according to someexample embodiments of the present invention is not limited thereto, andthe size of the rod-shaped LED LD may also be changed so as to accordwith a characteristic or requirement condition of a light emittingdevice, to which the rod-shaped LED LD is applied.

The first conductive semiconductor layer 11 may include, for example, atleast one n-type semiconductor layer. For example, the first conductivesemiconductor layer 11 may include any one semiconductor material amongInAlGaN, GaN, AlGaN, InGaN, AlN, and InN, and may include asemiconductor layer, in which a first conductive dopant, such as Si, Ge,and Sn, is doped. The material of the first conductive semiconductorlayer 11 is not limited thereto, and the first conductive semiconductorlayer 11 may be formed of various materials, other than theaforementioned materials.

The active layer 12 may be formed on the first conductive semiconductorlayer 11, and may be formed in a single or multiple quantum wellstructure. According to some example embodiments of the presentinvention, a clad layer, in which a conductive dopant is doped, may alsobe formed in an upper portion and/or a lower portion of the active layer12. For example, the clad layer may be implemented with an AlGaN layeror an InAlGaN layer. In addition, a material, such as AlGaN and AlInGaN,may be used as the active layer 12. When an electric field having avoltage (e.g., a predetermined voltage) or more is applied to therod-shaped LED LD, a pair of electron and hole is combined in the activelayer 12, so that the rod-shaped LED LD emits light.

The second conductive semiconductor layer 13 may be disposed on theactive layer 12, and may include a semiconductor layer having adifferent type from that of the first conductive semiconductor layer 11.For example, the second conductive semiconductor layer 13 may include atleast one p-type semiconductor layer. For example, the second conductivesemiconductor layer 13 may include any one semiconductor material amongInAlGaN, GaN, AlGaN, InGaN, AlN, and InN, and may include asemiconductor layer, in which a second conductive dopant, such as Mg, isdoped. The material of the second conductive semiconductor layer 13 isnot limited thereto, and the second conductive semiconductor layer 13may be formed of various materials, other than the aforementionedmaterial.

According to some example embodiments of the present invention, therod-shaped LED LD may further include another fluorescent layer, activelayer, semiconductor layer, and/or electrode layer in an upper portionand/or a lower portion of each layer, in addition to the aforementionedfirst conductive semiconductor layer 11, active layer 12, and secondconductive semiconductor layer 13. Further, the rod-shaped LED LD mayfurther include an insulating film 14. However, according to someexample embodiments of the present invention, the insulating film 14 mayalso be omitted, and may also be provided so as to cover a part of thefirst conductive semiconductor layer 11, the active layer 12, and thesecond conductive semiconductor layer 13. For example, the insulatingfilm 14 is provided to a portion, except for both ends of the rod-shapedLED LD, so that both ends of the rod-shaped LED LD may also be exposed.

For convenience of the description, FIG. 1 illustrates the state where apart of the insulating film 14 is removed, and a lateral surface of thecylinder of the rod-shaped LED LD may be completely surrounded by theinsulating film 14.

The insulating film 14 may be provided so as to surround at least a partof an outer peripheral surface of the first conductive semiconductorlayer 11, the active layer 12, and/or the second conductivesemiconductor layer 13. For example, the insulating film 14 may beprovided so as to surround at least an outer peripheral surface of theactive layer 12. According to some example embodiments of the presentinvention, the insulating film 14 may include a transparent insulatingmaterial. For example, the insulating film 14 may include one or moreinsulating materials selected from the group consisting of SiO₂, Si₃N₄,Al₂O₃, and TiO₂, but is not limited thereto, and various materialshaving an insulating property may be used.

In some example embodiments of the present invention, the insulatingfilm 14 itself may be formed of a hydrophobic material, or a hydrophobicfilm formed of a hydrophobic material may also be further provided ontothe insulating film 14. The hydrophobic material may be a materialcontaining fluorine exhibiting hydrophobicity. The hydrophobic materialmay be applied to the rod-shaped LED LD in a form of a Self-AssembledMonolayer (SAM), and in this case, may include octadecyltrichlorosilane,fluoroalkyltrichlorosilane, and perfluoroalkyltriethoxysilane. Further,the hydrophobic material may be a commercialized fluorine containedmaterial, such as Teflon™ or Cytop™, or a material corresponding to thecommercialized fluorine contained material.

When the insulating film 14 is provided to the rod-shaped LED LD, theactive layer 12 may be prevented from being short-circuited with a firstand/or second electrode. Further, the insulating film 14 is formed, sothat it is possible to minimize a defect of a surface of the rod-shapedLED LD, thereby improving life and efficiency of the rod-shaped LED LD.Further, when the plurality of rod-shaped LEDs LDs is closely disposed,the insulating film 14 may prevent an undesired short generable betweenthe rod-shaped LEDs LDs.

The rod-shaped LED LD may be used as light emitting sources of variouslight emitting devices. For example, the rod-shaped LED LD may be usedas a light device or a self-emitting display device.

FIG. 2 is a diagram illustrating a light emitting device according tosome example embodiments of the present invention. According to someexample embodiments of the present invention, FIG. 2 illustrates a lightemitting display device as an example of a light emitting device usingthe rod-shape LED LD, but the light emitting device according to thepresent disclosure is not limited to the light emitting display device.As one example, the light emitting device may also be another form oflight emitting device, such as a light device.

Referring to FIG. 2, the light emitting device according to some exampleembodiments of the present invention may include a timing controller110, a scan driver 120, a data driver 130, and a light emitting unit140. Like the present example embodiment, when the light emitting deviceis the light emitting display device, the light emitting unit 140 maymean an entirety of a pixel area implemented on a display panel.

The timing controller 110 may receive various control signals and imagedata required for driving the light emitting unit 140 from the outside(for example, a system transmitting image data). The timing controller110 realigns the received image data and transmits the realigned imagedata to the data driver 130. Further, the timing controller 110generates scan control signals and data control signals required fordriving the scan driver 120 and the data driver 130, and transmits thegenerated scan control signals and data control signals to the scandriver 120 and the data driver 130, respectively.

The scan driver 120 receives the scan control signal from the timingcontroller 110 and generates a scan signal in response to the receivedscan control signal. The scan signal generated by the scan driver 120may be supplied to unit emission areas EMA (for example, a pixel area,in which a pixel is provided) through scan lines S1 to Sn.

The data driver 130 may receive the data control signal and the imagedata from the timing controller 110, and generate a data signal inresponse to the received data control signal and image data. The datasignal generated by the data driver 130 may be output to data signals D1to Dm. The data signal output to the data lines D1 to Dm may be input tothe unit emission areas EMA of a horizontal pixel line selected by thescan signal.

The light emitting unit 140 may include the plurality of unit emissionareas EMA connected to the scan lines S1 and Sn and the data line D1 toDm. In some example embodiments of the present invention, the unitemission areas EMA may mean individual pixels.

Each of the unit emission areas EMA may include one or more rod-shapedLEDs LDs as illustrated in FIG. 1. As an example, each of the unitemission areas EMA may include one or more first color rod-shaped LEDsLDs, one or more second color rod-shaped LEDs LDs, and/or one or morethird rod-shaped LEDs LDs. The unit emission areas EMA selectively emitlight in response to the data signal input from the data lines D1 to Dmwhen the scan signal is supplied from the scan lines S1 to Sn. Forexample, each of the unit emission areas EMA emits light with luminancecorresponding to the received data signal during each frame period. Theunit emission area EMA receiving the data signal corresponding to blackluminance does not emit light during the corresponding frame period todisplay black. In the meantime, when the light emitting unit 140 is apixel unit of an active light emitting display panel, the light emittingunit 140 may further receive first and second pixel power source, inaddition to the scan signal and the data signal, and may be driven.

FIGS. 3A to 3E are circuit diagrams illustrating unit emission areas ofthe light emitting device according to some example embodiments of thepresent invention, and particularly, are circuit diagrams illustratingexamples of pixels forming a passive light emitting display panel. InFIGS. 3A to 3E, the unit emission area may include a j^(th) pixel (j isa natural number) in an i^(th) horizontal pixel line (i is a naturalnumber). As a non-limiting example related to the pixel illustrated inFIGS. 3A to 3E, the pixel may be one of a red pixel, a green pixel, ablue pixel, and a white pixel.

Referring to FIG. 3A, a pixel PXL includes a rod-shaped LED LD connectedbetween a scan line Si and a data line Dj. According to some exampleembodiments of the present invention, a first electrode (for example, ananode electrode of the rod-shaped LED LD may be connected to the scanline Si, and a second electrode (for example, a cathode electrode of therod-shaped LED LD may be connected to the data line Sj. When a voltageequal to or larger than a threshold voltage is applied between the firstelectrode and the second electrode, the rod-shaped LED LD emits lightwith luminance corresponding to a size of the applied voltage. That is,the emission of the pixel PXL may be controlled by adjusting voltages ofa scan signal applied to the scan line Si and/or a data signal appliedto the data line Dj.

Referring to FIG. 3B, according to some example embodiments of thepresent invention, a pixel PXL may include two or more rod-shaped LEDsLDs connected in parallel. In this case, luminance of the pixel PXL maycorrespond to a sum of brightness of the plurality of rod-shaped LEDsLDs. As described above, when the pixel PXL includes the plurality ofrod-shaped LEDs LDs, particularly, the large number of rod-shaped LEDsLDs, even though some of the rod-shaped LEDs LDs have defects, it ispossible to prevent the defects from causing a defect of the pixelitself.

Referring to FIG. 3C, according to some example embodiments of thepresent invention, a connection direction of a rod-shaped LED LDprovided in a pixel PXL may be changed. For example, a first electrode(anode electrode) of the rod-shaped LED LD may be connected to a dataline Dj and a second electrode (cathode electrode) of the rod-shaped LEDLD may be connected to a scan line Si. In the example embodiment of FIG.3A and the example embodiment of FIG. 3C, directions, in which thevoltages are applied between the scan lines Si and the data lines Dj,may be opposite to each other.

Referring to FIG. 3D, according to some example embodiments of thepresent invention, the pixel PXL according to the example embodiment ofFIG. 3C may also include two or more rod-shaped LEDs LDs connected inparallel.

Referring to FIG. 3E, according to some example embodiments of thepresent invention, a pixel PXL may include a plurality of rod-shapedLEDs LDs connected in different directions. As one example, the pixelPXL may include at least one rod-shaped LED LD, of which a firstelectrode (anode electrode) is connected to a scan line Si and a secondelectrode (cathode electrode) is connected to a data line Dj, and atleast one rod-shaped LED LD, of which the first electrode (anodeelectrode) is connected to the data line Dj and the second electrode(cathode electrode) is connected to the scan line Si.

According to some example embodiments of the present invention, thepixel PXL may be direct-current driven or alternating-current driven.When the pixel PXL in FIG. 3E is alternating-current driven, therod-shaped LEDs LDs connected in a forward direction may emit light, andthe rod-shaped LEDs LDs connected in a reverse direction may not emitlight. In the meantime, when the pixel PXL in FIG. 3E is direct-currentdriven, the rod-shaped LEDs LDs, which are connected in the forwarddirection according to a direction of applied voltage, emit light. Thatis, during the alternating-current driving, the rod-shaped LEDs LDsincluded in the pixel PXL of FIG. 3E may alternately emit lightaccording to a voltage direction.

FIGS. 4A to 4C are circuit diagrams illustrating unit emission areas ofthe light emitting device according to some example embodiments of thepresent invention, and particularly, are circuit diagrams illustratingexamples of pixels forming an active light emitting display panel. InFIGS. 4A to 4C, the same reference numeral is assigned to theconstituent element which is the same as or similar to the constituentelement of FIGS. 3A to 3E, and a detailed description thereof will beomitted. In some example embodiments of the present invention, a unitemission area may include one pixel PXL.

Referring to FIG. 4A, the pixel PXL includes one or more rod-shaped LEDsLDs, and a pixel circuit 144 connected to the one or more rod-shapedLEDs LDs.

A first electrode (for example, an anode electrode) of the rod-shapedLED LD is connected to a first pixel power source ELVDD via the pixelcircuit 144, and a second electrode (for example, a cathode electrode)of the rod-shaped LED LD is connected to a second pixel power sourceELVSS. The first pixel power source ELVDD and the second pixel powersource ELVSS may have different potentials. For example, the secondpixel power source ELVSS may have a potential lower than the potentialof the first pixel power source ELVDD by a threshold voltage of therod-shaped LED LD or more. Each of the rod-shaped LEDs LDs emits lightwith luminance corresponding to a driving current controlled by thepixel circuit 144.

Additionally, FIG. 4A illustrates an example embodiment in which thepixel includes only one rod-shaped LED LD, but embodiments of thepresent invention are not limited thereto. For example, the pixel PXLmay include a plurality of rod-shaped LEDs LDs connected in parallel.

According to some example embodiments of the present invention, thepixel circuit 144 includes first and second transistors M1 and M2, and astorage capacitor Cst. However, the structure of the pixel circuit 144is not limited to the example embodiment illustrated in FIG. 4A.

A first electrode of the first transistor (switching transistor) M1 isconnected to a data line Dj, and a second electrode thereof is connectedto a first node N1. Herein, the first electrode and the second electrodeof the first transistor M1 are different electrodes, and for example,when the first electrode is a source electrode, the second electrode maybe a drain electrode. Further, a gate electrode of the first transistorM1 is connected to a scan line Si. The first transistor M1 is turned onwhen a scan signal having a voltage (for example, a low voltage), bywhich the first transistor M1 may be turned on, is supplied from thescan line Si, to electrically connect the data line Dj and the firstnode N1. In this case, a data signal of a corresponding frame issupplied to the data line Dj, and thus the data signal is transmitted tothe first node N1. The data signal transmitted to the first node N1 ischarged in the storage capacitor Cst.

A first electrode of the second transistor (driving transistor) M2 isconnected to the first pixel power source ELVDD, and a second electrodethereof is connected to the first electrode of the rod-shaped LED LD.Further, a gate electrode of the second transistor M2 is connected tothe first node N1. The second transistor M2 controls the quantity ofdriving current supplied to the rod-shaped LED LD in response to thevoltage of the first node N1.

One electrode of the storage capacitor Cst is connected to the firstpixel power source ELVDD, and another electrode thereof is connected tothe first node N1. The storage capacitor Cst charges a voltagecorresponding to the data signal supplied to the first node N1, andmaintains the charged voltage until a data signal of a next frame issupplied.

For convenience of the description, FIG. 4A illustrates the pixelcircuit 144 having a comparatively simple structure including the firsttransistor M1 or transmitting the data signal to an internal side of thepixel PXL, the storage capacitor Cst for storing the data signal, andthe second transistor M2 for supplying the driving current correspondingto the data signal to the rod-shaped LED LD. However, the presentdisclosure is not limited thereto, and the structure of the pixelcircuit 144 may be variously modified and implemented. For example, thepixel circuit 144 may further include one or more transistor elements,such as a transistor element for compensating for a threshold voltage ofthe second transistor M2, a transistor element for initializing thefirst node N1, and/or a transistor element for controlling an emissiontime of the rod-shaped LED LD, or other circuit elements, such as aboosting capacitor or boosting the voltage of the first node N1, as amatter of course.

Further, FIG. 4A illustrates all of the transistors, for example, thefirst and second transistors M1 and M2, included in the pixel circuit144 are illustrated in a p-type, but the present disclosure is notlimited thereto. That is, at least one of the first and secondtransistors M1 and M2 included in the pixel circuit 144 may also bechanged to an n-type transistor.

Referring to FIG. 4B, according to some example embodiments of thepresent invention, first and second transistors M1 and M2 may beimplemented with N-type transistors. A configuration or an operation ofa pixel circuit 144 illustrated in FIG. 4B is similar to theconfiguration or the operation of the pixel circuit 144 illustrated inFIG. 4A, except for a change in a connection position of some elementsby the change in the type of the transistor. Accordingly, somedescription of the similar configuration or operation will be omittedfor brevity.

Referring to FIG. 4C, according to some example embodiments of thepresent invention, a pixel PXL may include a plurality of rod-shapedLEDs LDs connected in different directions. In this case, the pixel PXLmay be direct-current driven or alternating-current driven. This hasbeen described above with reference to FIG. 3E, so that a detaileddescription thereof will be omitted.

FIG. 5 is a top plan view illustrating a unit emission area of a lightemitting device according to some example embodiments of the presentinvention, and FIG. 6 is a cross-sectional view taken along line I-I′ ofFIG. 5. FIGS. 5 and 6 illustrate a pixel which is applicable to a lightemitting display panel that is a sort of light emitting device, but thepresent disclosure is not limited thereto. Further, FIG. 5 illustratesan example embodiment, in which one rod-shaped LED is included in a unitemission area, but the present disclosure is not limited thereto. Forexample, a plurality of rod-shaped LEDs may be provided in the unitemission area.

Further, FIG. 5 illustrates the case where the rod-shaped LED is alignedin a horizontal direction for convenience of the illustration, but thearrangement of the rod-shaped LED is not limited thereto. For example,the rod-shaped LED may also be aligned in a diagonal direction betweenfirst and second reflection electrodes.

Further, in FIG. 5, the unit emission area may be a pixel area includingone pixel PXL.

Referring to FIGS. 5 and 6, the light emitting device according to someexample embodiments of the present invention may include one or morepixels PXLs. Each pixel PXL may include a substrate SUB, first andsecond partition walls PW1 and PW2, a rod-shaped LED LD, first andsecond reflection electrodes REL1 and REL2, and first and second contactelectrodes CNE1 and CNE2.

The substrate SUB may be provided in various plate shapes. The substrateSUB may have an approximate quadrangular shape, particularly, arectangular shape. However, the shape of the substrate SUB is notlimited thereto, and the substrate SUB may have various shapes. Forexample, the substrate SUB may be provided in various shapes, such as apolygon having a closed shape including a straight side, a circle and anellipse including a curved side, and a semicircle and a half ellipseincluding a side formed of a straight line and a curved line. In someexample embodiments of the present invention, when the substrate SUB hasa straight side, at least a part of the corners of each shape may have acurved line. For example, when the substrate SUB has a rectangularshape, a portion, in which the adjacent straight sides meet, may bereplaced with a curve line having a curvature (e.g., a predeterminedcurvature). That is, in a vertex portion of the rectangular shape, bothadjacent ends may be connected to two adjacent straight sides and beformed of curve sides having a curvature (e.g., a predeterminedcurvature). The curvature may be differently set according to aposition. For example, the curvature may be changed according to a startposition of the curve line, a length of the curve line, and the like.

The substrate SUB may be formed of an insulating material, such asglass, organic polymer, and crystal. Further, the substrate SUB may beformed of a material having flexibility so as to be bendable orfoldable, and may have a single-layer structure of a multi-layerstructure.

For example, the substrate SUB may include at least one of polystyrene,polyvinyl alcohol, polymethyl methacrylate, polyethersulfone,polyacrylate, polyetherimide, polyethylene naphthalate, polyethyleneterephthalate, polyphenylene sulfide, polyarylate, polyimide,polycarbonate, triacetate cellulose, and cellulose acetate propionate.However, the material of the substrate SUB may be variously changed.

The first and second partition walls PW1 and PW2 may be provided so asto be spaced apart from each other on the substrate SUB. In some exampleembodiments of the present invention, the first and second partitionwalls PW1 and PW2 may be disposed so as to be spaced apart from eachother on the substrate SUB by a length of the rod-shaped LED LD or more.

Each of the first and second partition walls PW1 and PW2 may have atrapezoid shape having one surface SF1, which is in contact with thesubstrate SUB, an upper surface SF2, which faces the one surface SF1 andhas a smaller width in a first direction DR1 than a width of the onesurface SF1, and two lateral surfaces SF3, which connects the onesurface SF1 and the upper surface SF2, as illustrated in FIG. 6. The twolateral surfaces SF3 of the first and second partition walls PW1 and PW2may have an inclination having an angle (e.g., a predetermined angle).

In the first and second partition walls PW1 and PW2, gradients of thetwo lateral surfaces SF3 may be variously changed within the range, inwhich front efficiency of light emitted from both ends of the rod-shapedLED LD is improved.

The first and second partition walls PW1 and PW2 may be insulatingmaterials including an inorganic material or an organic material, but isnot limited thereto.

In some example embodiments of the present invention, the firstpartition wall PW1 and the second partition wall PW2 may be disposed onthe same plane on the substrate SUB, and may have the same height.

The first reflection electrode REL1 may be disposed on the firstpartition wall PW1, and the second reflection electrode REL2 may bedisposed on the second partition wall PW2. The first and secondreflection electrodes REL1 and REL2 are thinner than the first andsecond partition walls PW1 and PW2, so that the first and secondreflection electrodes REL1 and REL2 may be provided so as to correspondto the shapes of the first and second partition walls PW1 and PW2.Accordingly, each of the first and second reflection electrodes REL1 andREL2 may have a gradient corresponding to the gradient of the lateralsurfaces SF3 of the first and second partition walls PW1 and PW2.

When viewed on a plane, the first and second reflection electrodes REL1and REL2 may be provided so as to be spaced apart from each other on thesubstrate SUB. In some example embodiments of the present invention, thefirst and second reflection electrodes RL1 and REL2 may be disposed onthe substrate SUB so as to be spaced apart from each other by a lengthof the rod-shaped LED LD or more, but are not limited thereto. Forexample, the first and second reflection electrodes REL1 and REL2 may beprovided on the substrate SUB so as to be spaced apart from each otherby a distance shorter than the length of the rod-shaped LED LD tooverlap both ends of the rod-shaped LED LD, respectively. This will bedescribed below with reference to FIG. 16.

In some example embodiments of the present invention, the firstreflection electrode REL1 and the second reflection electrode REL2 maybe disposed on the same plane on the substrate SUB, and may have thesame height. When the first and second reflection electrodes REL1 andREL2 have the same height, the rod-shaped LED LD may be more stablypositioned on the first and second reflection electrodes REL1 and REL2.

In some example embodiments of the present invention, for convenience ofthe description, it is illustrated that the first and second reflectionelectrodes REL1 and REL2 are provided on the substrate SUB, on which thefirst and second partition walls PW1 and PW2 are provided, but thepresent disclosure is not limited thereto. For example, elements fordriving the light emitting device with a passive matrix or an activematrix may be further provided between the first and second reflectionelectrodes REL1 and REL2 and the substrate SUB. For example, when thelight emitting device is driven with the active matrix, signal lines, aninsulating layer, and/or a thin film transistor may be provided betweenthe first and second reflection electrodes REL1 and REL2 and thesubstrate SUB. The signal lines may include a scan line and a data line,and the thin film transistor may be connected to the signal lines, andmay include a gate electrode, a semiconductor pattern, a sourceelectrode, and a drain electrode. Any one of the source and the drainelectrodes may be connected to any one reflection electrode between thefirst and second reflection electrodes REL1 and REL2, and a data signalof the data line may be applied to the one reflection electrode throughthe thin film transistor. Here, the signal lines, the insulating layer,and/or the thin film transistor may be provided with various numbers andin various shapes as a matter of course. This will be described belowwith reference to FIGS. 17 and 18.

The first and second reflection electrodes REL1 and REL2 may be formedof a conductive material. The conductive material may include a metal,such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, and Cr, and an alloythereof, a conductive oxide, such as an indium tin oxide (ITO), anindium zinc oxide (IZO), a zinc oxide (ZnO), an indium tin zinc oxide(ITZO), and a conductive polymer, such as PEDOT, and the like. Further,the first and second reflection electrodes REL1 and REL2 may be formedof a single layer, but are not limited thereto, and may be formed ofmultiple layers, in which two or more materials among metals, alloys,conductive oxides, and conductive polymers are laminated.

Here, the materials of the first and second reflection electrodes REL1and REL2 are not limited to the aforementioned materials. For example,the first and second reflection electrodes REL1 and REL2 may be formedof a conductive materials having uniform reflectance so that lightemitted from both ends of the rod-shaped LED LD moves in a direction(for example, a front direction), in which the image is displayed.Further, the first and second reflection electrodes REL1 and REL2 may beformed of a different material from those of the first and secondpartition walls PW1 and PW2.

The first reflection electrode REL1 may be connected to a firstelectrode line S through a contact hole H, and may receive a voltageapplied to the first electrode line S. The second reflection electrodeREL2 may be extended from a second electrode line D and connected to thesecond electrode line D, and may receive a voltage applied to the secondelectrode line D. Accordingly, an electric field may be formed betweenthe first reflection electrode REL1 and the second reflection electrodeREL2.

The rod-shaped LED LD may be provided between the first and secondreflection electrodes REL1 and REL2 on the substrate SUB. Self-aligningof the rod-shaped LED LD may be induced by the electric field formedbetween the first and second reflection electrodes REL1 and REL2. Here,the rod-shaped LED LD may be provided in a rod shape extended in thefirst direction DR1.

The rod-shaped LED LD may include first and second conductivesemiconductor layers 11 and 13 (see FIG. 1), and an active layer 12 (seeFIG. 1) interposed between the first and second conductive semiconductorlayers 11 and 13.

The rod-shaped LED LD may have a first end portion EP1 and a second endportion EP2 along the first direction DR1. One of the first and secondconductive semiconductor layers 11 and 13 may be disposed at the firstend portion EP1, and the other of the first and second conductivesemiconductor layers 11 and 13 may be disposed at the second end portionEP2.

The first contact electrode CNE1 for electrically and/or physicallystably connecting the first reflection electrode REL1 and the first endportion EP1 of the rod-shaped LED LD may be disposed on the firstreflection electrode REL1.

The first contact electrode CNE1 may be in ohmic-contact with an upperportion of the first reflection electrode REL1. The first contactelectrode CNE1 may be formed of a transparent conductive materials, suchas an ITO, an IZO, and an ITZO, so as to allow the light emitted fromthe rod-shaped LED LD to pass through, but is not limited thereto. Forexample, the first contact electrode CNE1 may be formed of a conductivematerial including Al, Ti, Cr, and the like, of which a work function issmaller than about 4.1 eV.

When viewed on a plane, the first contact electrode CNE1 may cover thefirst reflection electrode REL1 and overlap the first reflectionelectrode REL1. Further, the first contact electrode CNE1 may partiallyoverlap the first end portion EP1 of the rod-shaped LED LD.

The second contact electrode CNE2 for electrically and/or physicallystably connecting the second reflection electrode REL2 and the secondend portion EP2 of the rod-shaped LED LD may be disposed on the secondreflection electrode REL2.

The second contact electrode CNE2 may be in ohmic-contact with an upperportion of the second reflection electrode REL2. The second contactelectrode CNE2 may be formed of the same material as that of the firstcontact electrode CNE1, but is not limited thereto. For example, thesecond contact electrode CNE2 may be formed of a conductive materialincluding Ni, an ITO, and the like, of which a work function is largerthan about 7.5 eV.

When viewed on a plane, the second contact electrode CNE2 may cover thesecond reflection electrode REL2 and overlap the second reflectionelectrode REL2. Further, the second contact electrode CNE2 may partiallyoverlap the second end portion EP2 of the rod-shaped LED LD.

Hereinafter, a structure of the light emitting device according to someexample embodiments of the present invention will be described accordingto a lamination sequence with reference to FIGS. 5 and 6.

The first and second partition walls PW1 and PW2 may be provided on thesubstrate SUB. The first and second partition walls PW1 and PW2 may bedisposed so as to be spaced apart from each other on the substrate SUB.The first and second partition walls PW1 and PW2 may be formed of aninsulating material.

The first reflection electrode REL1 may be disposed on the firstpartition wall PW1, and the second reflection electrode REL2 may bedisposed on the second partition wall PW2. The first and secondreflection electrodes REL1 and REL2 may be disposed on the same plane onthe corresponding partition walls PW1 and PW2, and may have the sameheight as those of the partition walls PW1 and PW2. Further, the firstand second reflection electrodes REL1 and REL2 may be formed of the samematerial. The first and second reflection electrodes REL1 and REL2 maybe disposed so as to be spaced apart from each other on the substrateSUB.

The rod-shaped LED LD may be aligned between the first and secondreflection electrodes REL1 and REL2. Self-aligning of the rod-shaped LEDLD may be induced by the electric field formed between the first andsecond reflection electrodes REL1 and REL2. The rod-shaped LED LD may beprovided on the substrate SUB so that both end portions, that is, thefirst and second end portions EP1 and EP2, of the rod-shaped LED LD, donot overlap the first and second reflection electrodes REL1 and REL2.

A first passivation layer PSV1 covering a part of an upper surface ofthe rod-shaped LED LD may be provided on the rod-shaped LED LD.Accordingly, the first and second end portions EP1 and EP2 of therod-shaped LED LD may be exposed to the outside. Here, the firstpassivation layer PSV1 may include any one insulating material betweenan inorganic insulating material and an organic insulating material.

The first contact electrode CNE1 may be disposed on the substrate SUB,on which the first passivation layer PSV1 is provided. The first contactelectrode CNE1 may cover the first reflection electrode REL1 and may beconnected to the first reflection electrode REL1. Further, the firstcontact electrode CNE1 may overlap the first end portion EP1 of therod-shaped LED LD and may be connected to the first end portion EP1 ofthe rod-shaped LED LD when viewed on a plane. Accordingly, the first endportion EP1 of the rod-shaped LED LD and the first reflection electrodeREL1 may be electrically and/or physical connected through the firstcontact electrode CNE1.

A second passivation layer PSV2 may be provided on the substrate SUB, onwhich the first contact electrode CNE1 is provided. The secondpassivation layer PSV2 may be provided on the substrate SUB so as tocover the first contact electrode CNE1 and the first passivation layerPSV1. Further, the second passivation layer PSV2 may include an openingfor exposing the second end portion EP2 of the rod-shaped LED LD and thesecond reflection electrode REL2 to the outside. Here, the secondpassivation layer PSV2 may be formed of the same material as that of thefirst passivation layer PSV1, but is not limited thereto.

The second contact electrode CNE2 may be disposed on the substrate SUB,on which the second passivation layer PSV2 is provided. The secondcontact electrode CNE2 may cover the second reflection electrode REL2and may be connected to the second reflection electrode REL2. Further,the second contact electrode CNE2 may overlap the second end portion EP2of the rod-shaped LED LD and may be connected to the second end portionEP2 of the rod-shaped LED LD when viewed on a plane. Accordingly, thesecond end portion EP2 of the rod-shaped LED LD and the secondreflection electrode REL2 may be electrically and/or physical connectedthrough the second contact electrode CNE2.

As described above, the second contact electrode CNE2 is disposed on thefirst contact electrode CNE1, so that the first and second contactelectrodes CNE1 and CNE2 may be disposed on different layers. In thiscase, each of the first and second electrodes CNE1 and CNE2 may beformed to include different materials. For example, the first contactelectrode CNE1 may be formed of a conductive material including Al, Ti,Cr, and the like, of which a work function is smaller than about 4.1 eVfor an ohmic contact between any one of the first and second conductivesemiconductor layers 11 and 13 of the rod-shaped LED LD and the firstreflection electrode REL1. The second contact electrode CNE2 may beformed of a conductive material including Ni, an ITO, and the like, ofwhich a work function is larger than about 7.5 eV for an ohmic contactbetween the other one of the first and second conductive semiconductorlayers 11 and 13 of the rod-shaped LED LD and the second reflectionelectrode REL2.

A third passivation layer PSV3 may be provided on the substrate SUB, onwhich the second contact electrode CNE2 is provided. The thirdpassivation layer PSV3 may prevent oxygen and moisture from permeatinginto the rod-shaped LED LD. The third passivation layer PSV3 may includean inorganic layer. The inorganic layer may include at least one of asilicon oxide, a silicon nitride, a silicon oxynitride, an aluminumoxide, a titanium oxide, a zirconium oxide, and a tin oxide.

As described above, in the light emitting device according to someexample embodiments of the present invention, the first and secondpartition walls PW1 and PW2 may be formed of an insulating material,which enables thicknesses and gradients of the first and secondpartition walls PW1 and PW2 to be relatively easily adjusted, comparedto a conductive material. In this case, heights and gradients of thefirst and second reflection electrodes REL1 and REL2 provided on theupper surfaces SF2 and the lateral surfaces SF3 of the first and secondpartition walls PW1 and PW2 may be easily changed by adjusting theheights and the gradients of the first and second partition walls PW1and PW2. Accordingly, it is possible to easily adjust the heights andthe gradients of the first and second partition walls PW1 and PW2 so asto improve front light emission efficiency of the rod-shaped LED LD. Forexample, in the case where front light emission efficiency of therod-shaped LED LD is optimal when the gradients of the first and secondreflection electrodes REL1 and REL2 are about 45° to 50°, the heightsand the gradients of the first and second reflection electrodes REL1 andREL2 may be easily adjusted by adjusting the heights and the gradientsof the first and second reflection electrodes REL1 and REL2.

In the existing light emitting device, the light emitted from both endportions of the rod-shaped LED LD moves in a front direction through thefirst and second reflection electrodes REL1 and REL2, which have theheights and the gradients of a level (e.g., a predetermined level) ormore, and are formed of a single metal material. Because the first andsecond reflection electrodes REL1 and REL2 have the heights and thegradients of the level (e.g., the predetermined level) or more and areformed of the single metal material, it may not easy to change theheights and the gradients of the first and second reflection electrodesREL1 and REL2 for improving front light emission efficiency of therod-shaped LED LD.

In this respect, in some example embodiments of the present invention,the first and second partition walls PW1 and PW2 may be disposed underthe first and second reflection electrodes REL1 and REL2 so as tocorrespond to the first and second reflection electrodes REL1 and REL2,respectively, and the heights and the gradients of the first and secondreflection electrodes REL1 and REL2 may be easily adjusted by adjustingthe heights and the gradients of the first and second partition wallsPW1 and PW2. Accordingly, front light emission efficiency of therod-shaped LED LD may be improved.

Further, in the light emitting device according to some exampleembodiments of the present invention, the rod-shaped LED LD may bealigned in a desired direction by easily adjusting the heights and thegradients of the first and second reflection electrodes REL1 and REL2.Accordingly, an aligning defect of the rod-shaped LED LD may beminimized.

Further, in the light emitting device according to some exampleembodiments of the present invention, the first and second contactelectrodes CNE1 and CNE2 may be disposed on different layers and may beformed so as to include different materials. In this case, a processmargin for a fine pattern process may be secured, compared to a generallight emitting device, in which the first and second contact electrodesCNE1 and CNE2 are disposed on the same layer and are formed to includethe same material. Here, the fine pattern process may mean a process ofperforming patterning so that the first and second contact electrodesCNE1 and CNE2 provided on the substrate SUB are spaced apart from eachother by an interval (e.g., a predetermined interval).

Further, in the light emitting device according to some exampleembodiments of the present invention, the first and second contactelectrodes CNE1 and CNE2 are formed to include different materials torapidly electrically and/or physically connect the first and secondreflection electrodes REL1 and REL2 and the rod-shaped LED LD, therebyfurther improving light emission efficiency of the rod-shaped LED LD.

FIGS. 7 to 14 are cross-sectional views sequentially illustrating amethod of manufacturing the light emitting device illustrated in FIG. 6.

Referring to FIGS. 6 and 7, first and second partition walls PW1 and PW2may be formed on a substrate SUB. The first and second partition wallsPW1 and PW2 may be spaced apart from each other on the substrate SUB.

Each of the first and second partition walls PW1 and PW2 may have atrapezoid shape including one surface SF1, which is in contact with thesubstrate SUB, an upper surface SF2 facing the one surface SF1, and twolateral surfaces SF3 connecting the one surface SF1 and the uppersurface SF2. Here, a width of the upper surface SF2 in a first directionDR1 (see FIG. 5) of the substrate SUB may be smaller than a width of theone surface SF1. Further, the two lateral surfaces SF3 may have agradient with an angle (e.g., a predetermined angle). The first andsecond partition walls PW1 and PW2 may be disposed on the same plane andmay have the same height.

Referring to FIGS. 6 and 8, first and second reflection electrodes REL1and REL2 may be formed on the first and second partition walls PW1 andPW2. The first reflection electrode REL1 may be formed on the firstpartition wall PW1, and the second reflection electrode REL2 may beformed on the second partition wall PW2. The first and second reflectionelectrodes REL1 and REL2 may be spaced apart from each other by aninterval (e.g., a predetermined interval). The first reflectionelectrode REL1 may correspond to a shape of the first partition wallPW1, and the second reflection electrode REL2 may correspond to a shapeof the second partition wall PW2. Accordingly, the first reflectionelectrode REL1 may have a gradient corresponding to the gradient of thefirst partition wall PW1, and the second reflection electrode REL2 mayhave a gradient corresponding to the gradient of the second partitionwall PW2.

Referring to FIGS. 6 and 9, a rod-shaped LED LD is injected and alignedon the substrate SUB, on which the first and second reflectionelectrodes REL1 and REL2 are provided. The rod-shaped LED LD may beinjected by using an inkjet printing method and the like, butembodiments of the present invention are not limited thereto. After therod-shaped LED LD is injected (or at the same time as the injection ofthe rod-shaped LED LD) by using the inkjet printing method and the like,self-aligning of the rod-shaped LED LD may be induced by an electricfield formed between the first and second reflection electrodes REL1 andREL2. Accordingly, the rod-shaped LED LD may be disposed between thefirst and second reflection electrodes REL1 and REL2. Here, both ends,that is, first and second end portions EP1 and EP2, of the rod-shapedLED LD may not overlap the first and second reflection electrodes REL1and REL2.

Referring to FIGS. 6 and 10, an insulating material layer is appliedonto a front surface of the substrate SUB, on which the rod-shaped LEDLD is provided, a first passivation layer PSV1 covering an upper surfaceof the rod-shaped LED LD may be formed by using a mask process and thelike. Here, the first passivation layer PSV1 may be patterned so as toexpose the first and second end portions EP1 and EP2 of the rod-shapedLED LD, but is not limited thereto. For example, the first passivationlayer PSV1 may be patterned by the mask process to expose the first endportion EP1 of the rod-shaped LED LD, and then may be patterned togetherwith a second passivation layer PSV2 formed by a subsequent process toexpose the second end portion EP2 of the rod-shaped LED LD.

Referring to FIGS. 6 and 11, a first contact electrode CNE1 may beformed on the substrate SUB, on which the first passivation layer PSV1is provided. The first contact electrode CNE1 may cover the firstreflection electrode REL1 and may be connected to the first reflectionelectrode REL1. Further, the first contact electrode CNE1 may cover thefirst end portion EP1 of the rod-shaped LED LD. The first contactelectrode CNE1 may electrically and/or physically connect the firstreflection electrode REL1 and the first end portion EP1 of therod-shaped LED LD.

Referring to FIGS. 6 and 12, an insulating material layer is applied onto the front surface of the substrate SUB, on which the first contactelectrode CNE1 is provided, and then the second passivation layer PSV2covering the first contact electrode CNE1 and the first passivationlayer PSV1 may be formed by using a mask process and the like. The firstand second passivation layers PSV1 and PSV2 may be formed to include thesame insulating material, but are not limited thereto. Here, the secondpassivation layer PSV2 may include an opening for exposing the secondend portion EP2 of the rod-shaped LED LD and the second reflectionelectrode REL2 to the outside.

Referring to FIGS. 6 and 13, a second contact electrode CNE2 may beformed on the substrate SUB, on which the second passivation layer PSV2is provided. The second contact electrode CNE2 may cover the secondreflection electrode REL2 and may be connected to the second reflectionelectrode REL2. Further, the second contact electrode CNE2 may cover thesecond end portion EP2 of the rod-shaped LED LD. The second contactelectrode CNE2 may electrically and/or physically connect the secondreflection electrode REL2 and the second end portion EP2 of therod-shaped LED LD.

Referring to FIGS. 6 and 14, a third passivation layer PSV3 may beformed on the substrate SUB, on which the second contact electrode CNE2is provided. The third passivation layer PSV3 may cover the secondpassivation layer PSV2 and the second contact electrode CNE2 forpreventing oxygen and moisture from permeating into the rod-shaped LEDLD.

FIG. 15 is a diagram illustrating a unit emission area of a lightemitting device according to some example embodiments of the presentinvention, and is a cross-sectional view taken along the line I-I′ ofFIG. 5. In some example embodiments of the present invention, in orderto avoid an overlapping description, a different matter from that of theexample embodiment will be mainly described. Parts, which are notparticularly described in the present example embodiment, follow theparts of the aforementioned example embodiment, and the same referencenumeral refers to the same element and the similar reference numeralrefers to the similar element. In FIGS. 5 and 15, a unit emission areamay be a pixel area including one pixel PXL.

Referring to FIGS. 5 and 15, the light emitting device according to someexample embodiments of the present invention may include one or morepixels PXLs. Each pixel PXL may include a substrate SUB, first andsecond partition walls PW1 and PW2, a rod-shaped LED LD, first andsecond reflection electrodes REL1 and REL2, and first and second contactelectrodes CNE1 and CNE2.

The first and second partition walls PW1 and PW2 may be disposed so asto be spaced apart from each other by an interval (e.g., a predeterminedinterval) on the substrate SUB, and may be formed to include aninsulating material, which enables thicknesses and gradients of thefirst and second partition walls PW1 and PW2 to be relatively easilyadjusted.

The first and second reflection electrodes REL1 and REL2 may be disposedon the corresponding partition walls PW1 and PW2, respectively. Forexample, the first reflection electrode REL1 may be disposed on thefirst partition wall PW1, and the second reflection electrode REL2 maybe disposed on the second partition wall PW2.

The rod-shaped LED LD may be disposed between the first and secondreflection electrodes REL1 and REL2 on the substrate SUB. The rod-shapedLED LD may include first and second conductive semiconductor layers 11and 13 (see, e.g., FIG. 1), and an active layer 12 (see, e.g., FIG. 1)interposed between the first and second conductive semiconductor layers11 and 13.

Here, an outer circumferential surface of the rod-shaped LED LD may becovered by an insulating film IL. The insulating film IL may be anelement for preventing an electric short generable when the active layer12 of the rod-shaped LED LD is in contact with the first and secondcontact electrodes CNE1 and CNE2. In some example embodiments of thepresent invention, it is illustrated that the insulating film ILsurrounds the remaining portion, except for first and second endportions EP1 and EP2, in the outer circumferential surface of therod-shaped LED LD, but the present disclosure is not limited thereto.For example, the insulating film IL may cover the entire outercircumferential surface of the rod-shaped LED LD including first andsecond end portions EP1 and EP2 for preventing durability of therod-shaped LED LD from being degraded. The insulating film IL mayinclude one or more insulating materials selected from the groupconsisting of SiO₂, Si₃N₄, Al₂O₃, and TiO₂, but is not limited thereto,and various materials having an insulating property may be used.

A first passivation layer PSV1 may be provided on the rod-shaped LED LD,of which the outer circumferential surface is covered by the insulatingfilm IL. The first passivation layer PSV1 may cover the insulating filmIL and the rod-shaped LED LD.

The first contact electrode CNE1 may be disposed on the substrate SUB,on which the first passivation layer PSV1 is provided. The first contactelectrode CNE1 may cover the first reflection electrode REL1 and may beconnected to the first reflection electrode REL1. Further, the firstcontact electrode CNE1 may overlap the first end portion EP1 of therod-shaped LED LD and may be connected to the first end portion EP1 ofthe rod-shaped LED LD.

A second passivation layer PSV2 may be provided on the substrate SUB, onwhich the first contact electrode CNE1 is provided.

The second contact electrode CNE2 may be disposed on the substrate SUB,on which the second passivation layer PSV2 is provided. The secondcontact electrode CNE2 may cover the second reflection electrode REL2and may be connected to the second reflection electrode REL2. Further,the second contact electrode CNE2 may overlap the second end portion EP2of the rod-shaped LED LD and may be connected to the second end portionEP2 of the rod-shaped LED LD.

A third passivation layer PSV3 may be provided on the substrate SUB, onwhich the second contact electrode CNE2 is provided.

FIG. 16 is a diagram illustrating a unit emission area of a lightemitting device according to some example embodiments of the presentinvention, and is a cross-sectional view taken along the line I-I′ ofFIG. 5. In some example embodiments of the present invention, in orderto avoid an overlapping description, a different matter from that of theexample embodiment will be mainly described. Parts, which are notparticularly described in the present example embodiment, follow theparts of the aforementioned example embodiment, and the same referencenumeral refers to the same element and the similar reference numeralrefers to the similar element. In FIGS. 5 and 16, a unit emission areamay be a pixel area including one pixel PXL.

Referring to FIGS. 5 and 16, the light emitting device according to someexample embodiments of the present invention may include one or morepixels PXLs. Each pixel PXL may include a substrate SUB, first andsecond partition walls PW1 and PW2, a rod-shaped LED LD, first andsecond reflection electrodes REL1 and REL2, and first and second contactelectrodes CNE1 and CNE2. Further, the pixel PXL may further include asupport member SM disposed between the substrate SUB and the rod-shapedLED LD.

The first and second partition walls PW1 and PW2 may be disposed so asto be spaced apart from each other by an interval (e.g., a predeterminedinterval) on the substrate SUB, and may be formed to include aninsulating material, which enables thicknesses and gradients of thefirst and second partition walls PW1 and PW2 to be relatively easilyadjusted.

The first and second reflection electrodes REL1 and REL2 may be providedon the corresponding partition walls PW1 and PW2, respectively. Forexample, the first reflection electrode REL1 may be disposed on thefirst partition wall PW1, and the second reflection electrode REL2 maybe disposed on the second partition wall PW2.

The first and second reflection electrodes REL1 and REL2 may be providedwhile being spaced apart from each other by a distance shorter than adistance of the rod-shaped LED LD on the substrate so as to overlap bothend portions of the rod-shaped LED LD, respectively, when viewed on aplane. That is, the first reflection electrode REL1 may be disposed onthe first partition wall PW1 so as to overlap a first end portion EP1between both end portions of the rod-shaped LED LD when viewed on aplane. Further, the second reflection electrode REL2 may be disposed onthe second partition wall PW2 so as to overlap the second end portionEP2 facing the first end portion EP1 when viewed on a plane.Accordingly, the first end portion EP1 of the rod-shaped LED LD may bedisposed on the first reflection electrode REL1, and the second endportion EP2 of the rod-shaped LED LD may be disposed on the secondreflection electrode REL2.

The support member SM may be disposed between the rod-shaped LED LD andthe substrate SUB. For example, the support member SM may be disposed onthe substrate SUB so as to be filled in a vertical space between thesubstrate SUB and the rod-shaped LED LD. The support member SM stablysupports the rod-shaped LED LD, thereby preventing the rod-shaped LED LDaligned between the first and second reflection electrodes REL1 and REL2from deviating. The support member SM may include an insulatingmaterial. In some example embodiments of the present invention, thesupport member SM may have the same height as those of the first andsecond reflection electrodes REL1 and REL2, but is not limited thereto.For example, the support member may also have a different height fromthose of the first and second reflection electrodes REL1 and REL2.

The rod-shaped LED LD may be aligned on the support member SM. In thiscase, the first end portion EP1 of the rod-shaped LED LD may correspondto the first reflection electrode REL1, the second end portion EP2 ofthe rod-shaped LED LD may correspond to the second reflection electrodeREL2, and the remaining portion, except for the first and second endportions EP1 and EP2, in the rod-shaped LED LD may correspond to thesupport member SM.

A first passivation layer PSV1 may be provided on the rod-shaped LED LD.The first passivation layer PSV1 may cover the rod-shaped LED LD.

The first contact electrode CNE1 may be disposed on the substrate SUB,on which the first passivation layer PSV1 is provided. The first contactelectrode CNE1 may be disposed on the first reflection electrode REL1and the first end portion EP1 of the rod-shaped LED LD and electricallyand/or physically connect the first reflection electrode REL1 and thefirst end portion EP1 of the rod-shaped LED LD.

A second passivation layer PSV2 may be provided on the substrate SUB, onwhich the first contact electrode CNE1 is provided.

The second contact electrode CNE2 may be disposed on the substrate SUB,on which the second passivation layer PSV2 is provided. The secondcontact electrode CNE1 may be disposed on the second reflectionelectrode REL2 and the second end portion EP2 of the rod-shaped LED LDand electrically and/or physically connect the second reflectionelectrode REL2 and the second end portion EP2 of the rod-shaped LED LD.

A third passivation layer PSV3 may be provided on the substrate SUB, onwhich the second contact electrode CNE2 is provided.

FIG. 17 is a top plan view illustrating a unit emission area of a lightemitting device according to some example embodiments of the presentinvention, and FIG. 18 is a cross-sectional view taken along the lineII-II′ of FIG. 17.

FIGS. 17 and 18 illustrate a pixel which is applicable to a lightemitting display panel that is a sort of light emitting device, but thepresent disclosure is not limited thereto. Further, FIG. 17 illustratesan example embodiment, in which a plurality of rod-shaped LEDs isincluded in a unit emission area, but the present disclosure is notlimited thereto. For example, one rod-shaped LED may be provided in theunit emission area.

Further, FIG. 17 illustrates the case where the plurality of rod-shapedLEDs is aligned in a horizontal direction for convenience of theillustration, but the arrangement of the plurality of rod-shaped LEDs isnot limited thereto. For example, the plurality of rod-shaped LEDs mayalso be aligned in a diagonal direction between first and secondreflection electrodes.

Further, in FIG. 17, for convenience of the illustration, theillustration of a thin film transistor connected to the plurality ofrod-shaped LEDs and signal lines connected to the thin film transistoris omitted.

In some example embodiments of the present invention, in order to avoidan overlapping description, a different matter from that of the exampleembodiment will be mainly described. Parts, which are not particularlydescribed in the present example embodiment, follow the parts of theaforementioned example embodiment, and the same reference numeral refersto the same element and the similar reference numeral refers to thesimilar element. In FIG. 17, the unit emission area may be a pixel areaincluding one pixel PXL including first to third sub pixels SPXL1,SPXL2, and SPXL3.

Referring to FIGS. 17 and 18, the light emitting device according tosome example embodiments of the present invention may include one ormore pixels PXLs. Each pixel PXL may include first to third sub pixelsSPXL1, SPXL2, and SPXL3.

The first sub pixel SPXL1 may include a substrate SUB, a firstrod-shaped LED LD1, a circuit element unit provided between thesubstrate SUB and the first rod-shaped LED LD1, and first and secondreflection electrodes REL1 and REL2.

The second sub pixel SPXL2 may include the substrate SUB, a secondrod-shaped LED LD2, a circuit element unit provided between thesubstrate SUB and the second rod-shaped LED LD2, and first and secondreflection electrodes REL1 and REL2.

The third sub pixel SPXL3 may include the substrate SUB, a thirdrod-shaped LED LD3, a circuit element unit provided between thesubstrate SUB and the third rod-shaped LED LD3, and first and secondreflection electrodes REL1 and REL2.

The circuit element unit provided in each of the first to third subpixels SPXL1, SPXL2, and SPXL3 may include first and second transistorsT1 and T2 and a storage capacitor provided on the substrate SUB.

The first transistor T1 may be a switching transistor for transferring adata signal into the corresponding sub pixels SPXL1, SPXL2, and SPXL3,and the second transistor T2 may be a driving transistor for supplying adriving current corresponding to the data signal to the correspondingrod-shaped LEDs LD1, LD2, and LD3. The storage capacitor Cst may chargea voltage corresponding to the data signal, and may maintain the chargedvoltage until a data signal of a next frame is supplied.

Each of the first to third rod-shaped LEDs LD1, LD2, and LD3 may be alight emitting diode emitting light of a different color. For example,the first rod-shaped LED LD1 may be a red light emitting diode emittingred light, the second rod-shaped LED LD2 may be a green light emittingdiode emitting green light, and the third rod-shaped LED LD3 may be ablue light emitting diode emitting blue light.

A first end portion EP1 between both end portions of the firstrod-shaped LED LD1 may be connected to the first reflection electrodeREL1 connected to a first electrode line SL extended in a firstdirection DR1 of the substrate SUB. A second end portion EP2 betweenboth end portions of the first rod-shaped LED LD1 may be connected tothe second reflection electrode REL2 connected to a second-one electrodeline DL1 extended in a second direction DR2 crossing the first directionDR1.

A first end portion EP1 between both end portions of the secondrod-shaped LED LD2 may be connected to the first reflection electrodeREL1 connected to the first electrode line SL. A second end portion EP2between both end portions of the second rod-shaped LED LD2 may beconnected to the second reflection electrode REL2 connected to asecond-two electrode line DL2 extended in the second direction DR2.

A first end portion EP1 between both end portions of the thirdrod-shaped LED LD3 may be connected to the first reflection electrodeREL1 connected to the first electrode line SL. A second end portion EP2between both end portions of the third rod-shaped LED LD3 may beconnected to the second reflection electrode REL2 connected to asecond-three electrode line DL3 extended in the second direction DR2.

In some example embodiments of the present invention, the second andthird sub pixels SPXL2 and SPXL3 may be provided in the same form,except for the first rod-shaped LED LD1 of the first sub pixel SPXL1.Accordingly, the descriptions of the second and third sub pixels SPXL2and SPXL3 will be substituted with the description of the first subpixel SPXL1.

The first sub pixel SPXL1 may further include a partition wall PW, andfirst and second contact electrodes CNE1 and CNE2.

The partition wall PW may be provided in plural on the substrate SUB andmay be spaced apart from each other. The partition wall PW may have atrapezoid shape including one surface SF1, which is in contact with thesubstrate SUB, an upper surface SF2 facing the one surface SF1, and twolateral surfaces SF3 connecting the one surface SF1 and the uppersurface SF2 as illustrated in FIG. 18.

The first reflection electrode REL1 may be disposed on the partitionwall PW. The first reflection electrode REL1 may be disposed so as tocorrespond to a shape of the partition wall PW. Accordingly, the firstreflection electrode REL1 may have a gradient, which is the same as orsimilar to a gradient of the corresponding partition wall PW.

The first reflection electrode REL1 and the partition wall PW may beformed of different materials. For example, the first reflectionelectrode REL1 may be formed of a conductive material, and the partitionwall PW may be formed of an insulating material. Here, the secondreflection electrode REL2 may include the same material as that of thefirst reflection electrode REL1.

The first reflection electrode REL1 may be connected to the firstelectrode line SL through a first contact hole CH1 and may receive avoltage applied to the first electrode line SL. The second reflectionelectrode REL2 may be extended from the second-one electrode line DL1and connected to the second-one electrode line DL1, and may receive avoltage applied to the second-one electrode line DL1. Accordingly, anelectric field may be formed between the first reflection electrode REL1and the second reflection electrode REL2.

When viewed on a plane, the first reflection electrode REL1 connected tothe first electrode line SL may be branched to a left side and a rightside of the second reflection electrode REL2. Accordingly, the branchedfirst reflection electrodes REL1 s and the second reflection electrodeREL2 may be alternately disposed on the substrate SUB. Particularly,when viewed on a plane, the second reflection electrode REL2 may bedisposed between the branched first reflection electrodes REL1 s. Inthis case, an electric field may be formed between the first reflectionelectrode REL1 branched to the left side of the second reflectionelectrode REL2 and the second reflection electrode REL2. Further, anelectric field may be formed between the first reflection electrode REL1branched to the right side of the second reflection electrode REL2 andthe second reflection electrode REL2. For convenience of thedescription, hereinafter, the first reflection electrode REL1 branchedto the left side of the second reflection electrode REL2 will bereferred to as the first-one reflection electrode REL1, and the firstreflection electrode REL1 branched to the right side of the secondreflection electrode REL2 will be referred to as the first-tworeflection electrode REL1.

The first rod-shaped LED LD1 may be provided between the first andsecond reflection electrodes REL1 and REL2 on the substrate SUB.Particularly, the first rod-shaped LED LD1 may be provided between thefirst-one reflection electrode REL1 and the second reflection electrodeREL2, and between the second reflection electrode REL2 and the first-tworeflection electrode REL1. For convenience of the description, the firstrod-shaped LED LD1 provided between the first-one reflection electrodeREL1 and the second reflection electrode REL2 will be referred to as thefirst-one rod-shaped LED LD1, and the first rod-shaped LED LD1 providedbetween the second reflection electrode REL2 and the first-tworeflection electrode REL1 will be referred to as the first-tworod-shaped LED LD1. Self-aligning of the first rod-shaped LED LD1 may beinduced by the electric field formed between the first-one and secondreflection electrodes REL1 and REL2. Self-aligning of the first-tworod-shaped LED LD1 may be induced by the electric field formed betweenthe first-two and second reflection electrodes REL1 and REL2. Here, bothend portions EP1 and EP2 of the first-two rod-shaped LED LD1 may bedisposed to be opposite to both end portions EP1 and EP2 of thefirst-one rod-shaped LED LD1. That is, the second end portion EP2 of thefirst-one rod-shaped LED LD1 and the second end portion EP2 of thefirst-two rod-shaped LED LD1 may be disposed while facing each other onthe substrate SUB.

The first contact electrode CNE1 for electrically and/or physicallyconnecting the first end portion EP1 of the first-one rod-shaped LED LD1and the first-one reflection electrode REL1 may be disposed on thefirst-one reflection electrode REL1. Further, the first contactelectrode CNE1 for electrically and/or physically stably connecting thefirst-two reflection electrode REL1 and the first end portion EP1 of thefirst-two rod-shaped LED LD1 may be disposed on the first-two reflectionelectrode REL1. When viewed on a plane, the first contact electrodesCNE1 s may cover the first-one and first-two reflection electrodes REL1s, respectively, and overlap the first-one and first-two reflectionelectrodes REL1, respectively. Further, the first contact electrode CNE1may overlap the first end portion EP1 of each of the first-one andfirst-two rod-shaped LEDs LD1 s.

The second contact electrode CNE2 for electrically and/or physicallystably connecting the second reflection electrode REL2 and the secondend portion EP2 of each of the first-one and first-two rod-shaped LEDsLD1 s may be disposed on the second reflection electrode REL2. Whenviewed on a plane, the second contact electrode CNE2 may cover thesecond reflection electrode REL2 and overlap the second reflectionelectrode REL2. Further, the second contact electrode CNE2 may overlapthe second end portion EP2 of each of the first-one and first-tworod-shaped LEDs LD1 s.

Hereinafter, a structure of the light emitting device according to someexample embodiments of the present invention will be described accordingto a lamination sequence with reference to FIGS. 17 and 18.

A buffer layer BFL may be provided on the substrate SUB. The bufferlayer BFL may prevent impurities from being diffused from the substrateSUB, and may improve the degree of flatness of the substrate SUB. Thebuffer layer BFL may be provided of a single layer, but may also beprovided of multiple layers including two or more layers. The bufferlayer BFL may be an inorganic insulating layer formed of an inorganicmaterial.

A semiconductor pattern SA included in each of the first and secondtransistors T1 and T2 may be provided on the buffer layer BFL. Thesemiconductor pattern SA may include a source region, a drain region,and a channel region provided between the source region and the drainregion.

A gate insulating layer GI may be provided on the substrate SUB, onwhich the semiconductor pattern SA is provided.

A gate electrode GE included in each of the first and second transistorsT1 and T2 may be disposed on the gate insulating layer GI. Further, thefirst electrode line SL may be disposed on the gate insulating layer GI.Here, the gate electrode GE may be connected to a scan line, to which ascan signal is applied.

First and second interlayer insulating layers ILD1 and ILD2 may beprovided on the substrate SUB, on which the gate electrode GE and thelike are provided.

First and second electrodes EL1 and EL2 included in each of the firstand second transistors T1 and T2 may be disposed on the secondinterlayer insulating layer ILD2. Further, a bridge pattern BRP may bedisposed on the second interlayer insulating layer ILD2.

The first and second electrodes EU and EL2 are different electrodes, andfor example, when the first electrode EL1 is a drain electrode, thesecond electrode EL2 may be a source electrode. In this case, the firstelectrode EL1 of the second transistor T2 may be connected to the secondreflection electrode REL2.

The bridge pattern BRP may be connected to the first electrode line SLthrough the first contact hole CH1, which sequentially passes throughthe first and second interlayer insulating layers ILD1 and ILD2.

An insulating layer INS may be provided on the substrate SUB, on whichthe bridge pattern BRP and the like are provided. The insulating layerINS may be an organic insulating material including an organic material.

The partition walls PWs may be provided on the insulating layer INS. Thepartition walls PWs may be disposed while being spaced apart from oneanother by an interval (e.g., a predetermined interval) on theinsulating layer INS. Further, a pixel defining layer PDL defining theunit emission area of the light emitting device may be provided on theinsulating layer INS. The pixel defining layer PDL and the partitionwall PW may be formed of the same insulating material and may beprovided on the same layer.

The first-one and first-two reflection electrodes REL1 and the secondreflection electrode REL2 may be disposed on the substrate SUB, on whichthe partition walls PWs are provided. Accordingly, the first-one andfirst-two reflection electrodes REL1 and the second reflection electrodeREL2 may be disposed on the substrate SUB while being spaced apart fromone another by an interval (e.g., a predetermined interval). Forexample, when viewed on a plane, the second reflection electrode REL2may be disposed between the first-one reflection electrode REL1 and thefirst-two reflection electrode REL1.

Here, the first-one reflection electrode REL1 may be connected to thebridge pattern BRP through the second contact hole CH2 passing throughthe insulating layer INS. Accordingly, the first-one reflectionelectrode REL1 may be connected to the first electrode line SL1 throughthe bridge pattern BRP and the first and second contact holes CH1 andCH2. Accordingly, the voltage applied to the first electrode line SL1may be applied to the first-one reflection electrode REL1. The first-tworeflection electrode REL1 is branched from the first-one reflectionelectrode REL1, so that the voltage applied to the first electrode lineSL1 may also be applied to the first-two reflection electrode REL1.

The second reflection electrode REL2 may be connected to the firstelectrode EL1 of the second transistor T2 through an opening of theinsulating layer INS, which exposes the first electrode EL1 of thesecond transistor T2. Further, the second reflection electrode REL2 maybe extended from the second-one electrode line DL1 to be connected tothe second-one electrode line DL1. Finally, the voltage applied to thefirst electrode EL1 of the second transistor T2 may be applied to thesecond-one electrode line DL1 and the second reflection electrode REL2.

The first-one rod-shaped LED LD1 may be aligned between the first-onereflection electrode REL1 and the second reflection electrode REL2.Further, the first-two rod-shaped LED LD1 may be aligned between thefirst-two reflection electrode REL1 and the second reflection electrodeREL2.

A first passivation layer PSV1 covering a part of an upper surface ofeach of the first-one and first-two rod-shaped LEDs LD1 s may beprovided on the first-one and first-two rod-shaped LEDs LD1 s.Accordingly, the first and second end portions EP1 and EP2 of each ofthe first-one and first-two rod-shaped LEDs LD1 s may be exposed to theoutside.

The first contact electrode CNE1 may be disposed on the substrate SUB,on which the first passivation layer PSV1 is provided. The first contactelectrode CNE1 may cover the first-one reflection electrode REL1 and thefirst-two reflection electrode REL1 and may be connected to thecorresponding first reflection electrode REL1. Further, the firstcontact electrode CNE1 may cover the first end portion EP1 of each ofthe first-one and first-two rod-shaped LEDs LD1 s. The first contactelectrode CNE1 may electrically and/or physically connect the first-onereflection electrode REL1 and the first end portion EP1 of the first-onerod-shaped LED LD1. Further, the first contact electrode CNE1 mayelectrically and/or physically connect the first-two reflectionelectrode REL1 and the first end portion EP1 of the first-two rod-shapedLED LD1.

A second passivation layer PSV2 may be provided on the substrate SUB, onwhich the first contact electrode CNE1 is provided.

The second contact electrode CNE2 may be disposed on the substrate SUB,on which the second passivation layer PSV2 is provided. The secondcontact electrode CNE2 may cover the second reflection electrode REL2and may be connected to the second reflection electrode REL2. Further,the second contact electrode CNE2 may cover the second end portion EP2of each of the first-one and first-two rod-shaped LEDs LD1 s. The secondcontact electrode CNE2 may electrically and/or physically connect oneside of the second reflection electrode REL2 and the second end portionEP1 of the first-one rod-shaped LED LD1. Further, the second contactelectrode CNE2 may electrically and/or physically connect the other sideof the second reflection electrode REL2 and the second end portion EP2of the first-two rod-shaped LED LD1.

A third passivation layer PSV3 may be provided on the substrate SUB, onwhich the second contact electrode CNE2 is provided. The thirdpassivation layer PSV3 may cover the second passivation layer PSV2 andthe second contact electrode CNE2 for preventing oxygen and moisturefrom permeating into the first rod-shaped LED LD1.

As described above, in the light emitting device according to someexample embodiments of the present invention, it is possible to easilyadjust heights and gradients of the first-one and first-two reflectionelectrodes REL1 by disposing the partition wall PW under the first-oneand first-two reflection electrodes REL1 and adjusting a height and agradient of the partition wall PW. Accordingly, front light emissionefficiency of the first-one and first-two rod-shaped LEDs LD1 s may beimproved.

Further, in the light emitting device according to some exampleembodiments of the present invention, the first-one and first-tworod-shaped LEDs LD1 s may be aligned in a desired direction by easilyadjusting the heights and the gradients of the first-one and first-tworeflection electrodes REL1. Accordingly, the aligning defect of thefirst-one and first-two rod-shaped LEDs LD1 s may be minimized.

FIGS. 19 to 27 are cross-sectional views sequentially illustrating amethod of manufacturing the light emitting device illustrated in FIG.18.

Referring to FIGS. 18 and 19, first and second transistors T1 and T2 anda bridge pattern BRP may be formed on a substrate SUB. An insulatinglayer INS including a second contact hole CH2 exposing a part of thebridge pattern BRP and an opening exposing a part of a first electrodeof the second transistor T2 may be formed on the first and secondtransistors T1 and T2 and the bridge pattern BRP.

Referring to FIGS. 18 and 20, partition walls PWs and a pixel defininglayer PDL may be formed on the substrate SUB, on which the bridgepattern BRP and the like are formed. The partition wall PW and the pixeldefining layer PDL may be spaced apart from each other on the substrateSUB by an interval (e.g., a predetermined interval). The partition wallPW may have a trapezoid shape including one surface SF1, which is incontact with the substrate SUB, an upper surface SF2 facing the onesurface SF1, and two lateral surfaces SF3 connecting the one surface SF1and the upper surface SF2, and the number of partition walls PW providedis two or more.

Referring to FIGS. 18 and 21, first and second reflection electrodesREL1 and REL2 may be formed on the substrate SUB, on which the partitionwalls PWs and the like are formed. The first reflection electrode REL1may be formed on the partition wall PW and may be connected to thebridge pattern BRP through a second contact hole CH2. The secondreflection electrode REL2 may be connected to a first electrode EL1 ofthe second transistor T2 through the opening of the insulating layerINS. The first reflection electrode REL1 may be branched and disposed ata left side and a right side of the second reflection electrode REL2 asillustrated in FIG. 17. The first reflection electrode REL1 may have aninclination corresponding to a gradient of the partition wall PW.

Referring to FIGS. 18 and 22, a first rod-shaped LED LD1 may be alignedon the substrate SUB, on which the first and second reflectionelectrodes REL1 and REL2 are provided. The first rod-shaped LED LD1 maybe aligned between the first reflection electrode REL1, which isdisposed at the left side of the second reflection electrode REL2, andthe second reflection electrode REL2. Further, the first rod-shaped LEDLD1 may be aligned between the first reflection electrode REL1, which isdisposed at the right side of the second reflection electrode REL2, andthe second reflection electrode REL2.

Referring to FIGS. 18 and 23, an insulating material layer is appliedonto a front surface of the substrate SUB, to which the first rod-shapedLED LD1 is provided, and then an insulating pattern PSV1′ covering asecond end portion EP2 and an upper surface of the first rod-shaped LEDLD1 and the pixel defining layer PDL may be formed by using a maskprocess and the like. Here, the first end portion EP1 of the firstrod-shaped LED LD1 may be exposed to the outside.

Referring to FIGS. 18 and 24, a first contact electrode CNE1 may beformed on the substrate SUB, on which the insulating pattern PSV1′ isformed. The first contact electrode CNE1 may cover the first reflectionelectrode REL1 and may be connected to the first reflection electrodeREL1. Further, the first contact electrode CNE1 may cover the first endportion EP1 of the first-rod-shaped LED LD1. The first contact electrodeCNE1 may electrically and/or physically connect the first reflectionelectrode REL1 and the first end portion EP1 of the first-rod-shaped LEDLD1.

Referring to FIGS. 18 and 25, an insulating material layer is applied onto the front surface of the substrate SUB, on which the first contactelectrode CNE1 is formed, and then a second passivation layer PSV2exposing the second contact electrode CNE2 and the second end portionEP2 of the first rod-shaped LED LD1 may be formed by using a maskprocess and the like. Here, the insulating pattern PSV1′ illustrated inFIG. 24 may be patterned at the same time by the mask process to becomethe first passivation layer PSV1 exposing the second end portion EP2 ofthe first rod-shaped LED LD1 and the second reflection electrode REL2.

Referring to FIGS. 18 and 26, a second contact electrode CNE2 may beformed on the substrate SUB, on which the second passivation layer PSV2is formed. The second contact electrode CNE2 may cover the secondreflection electrode REL2 and may be connected to the second reflectionelectrode REL2. Further, the second contact electrode CNE2 may cover thesecond end portion EP2 of the first rod-shaped LED LD1. The secondcontact electrode CNE2 may electrically and/or physically connect thesecond reflection electrode REL2 and the second end portion EP1 of thefirst rod-shaped LED LD1.

Referring to FIGS. 18 and 27, a third passivation layer PSV3 may beformed on the substrate SUB, on which the second contact electrode CNE2is provided. The third passivation layer PSV3 may cover the secondpassivation layer PSV2 and the second contact electrode CNE2 forpreventing oxygen and moisture from permeating into the first rod-shapedLED LD1.

The light emitting device according to INR 16 Lakhs may be applied tovarious display devices. For example, the light emitting device may beapplied to a television, a notebook computer, a mobile phone, a smartphone, a smart pad (PD), a Portable Multimedia Player (PDP), a PersonalDigital Assistant (PDA), a navigation device, various wearable devices,such as a smart watch, and the like.

Although aspects of some example embodiments of the present inventionhave been described with reference to some example embodiments, thoseskilled in the art may understand that the present disclosure may bevariously modified and changed within a scope without departing from thespirit and the area of the present disclosure described in theaccompanying claims and their equivalents.

Accordingly, the technical scope of the present invention is not limitedto the contents described in the detailed description of thespecification, but shall be defined by the claims and their equivalents.

What is claimed is:
 1. A light emitting device, comprising: a substrate;a light emitting element on the substrate, the light emitting elementhaving a first end portion and a second end portion arranged in alongitudinal direction; one or more partition walls disposed on thesubstrate, the one or more partition walls being spaced apart from thelight emitting element; a first reflection electrode adjacent the firstend portion of the light emitting element; a second reflection electrodeadjacent the second end portion of the light emitting element; a firstcontact electrode connected to the first reflection electrode and thefirst end portion of the light emitting element; an insulating layer onthe first contact electrode, the insulating layer having an openingexposing the second end portion of the light emitting element and thesecond reflection electrode to the outside; and a second contactelectrode on the insulating layer, the second contact electrode beingconnected to the second reflection electrode and the second end portionof the light emitting element through the opening.
 2. The light emittingdevice of claim 1, wherein any one of the first and second reflectionelectrodes is on the partition wall.
 3. The light emitting device ofclaim 2, wherein the first and second reflection electrodes and thepartition wall comprise different materials.
 4. The light emittingdevice of claim 3, wherein the partition wall includes an insulatingmaterial and the first and second reflection electrodes include aconductive material.
 5. The light emitting device of claim 1, whereinwhen viewed on a plane, the first contact electrode overlaps the firstreflection electrode, and the second contact electrode overlaps thesecond reflection electrode.
 6. The light emitting device of claim 1,wherein the light emitting element is a light emitting diode shaped likea cylinder or a polyprism having a micro scale or a nano scale.
 7. Thelight emitting device of claim 6, wherein the light emitting elementcomprises: a first conductive semiconductor layer in which a firstconductive dopant is doped; a second conductive semiconductor layer inwhich a second conductive dopant is doped; and an active layer disposedbetween the first and second conductive semiconductor layers.
 8. Thelight emitting device of claim 7, wherein any one of the first andsecond contact electrodes includes a conductive material, of which awork function is less than 4.1 eV, and the other of the first and secondcontact electrodes includes a conductive material, of which a workfunction is larger than 7.5 eV.
 9. The light emitting device of claim 1,wherein each of the first and second reflection electrodes is on thepartition wall.
 10. The light emitting device of claim 1, furthercomprising: a support member between the substrate and the lightemitting element.
 11. The light emitting device of claim 10, wherein thesupport member includes an insulating material.
 12. The light emittingdevice of claim 1, further comprising: an insulating film on an outercircumferential surface of the light emitting element.
 13. A displaydevice, comprising: a substrate including a pixel area; a pixel in thepixel area and having one or more thin film transistors; and a lightemitting device on the thin film transistor and connected to the thinfilm transistor, wherein the light emitting device comprises: aplurality of light emitting elements on the substrate, the plurality oflight emitting elements each having a first end portion and a second endportion arranged in a longitudinal direction; one or more partitionwalls spaced apart from each of the plurality of light emittingelements; a first reflection electrode adjacent the first end portion ofeach light emitting element; a second reflection electrode adjacent thesecond end portion of each light emitting element; a first contactelectrode connected to the first reflection electrode and the first endportion; an insulating layer on the first contact electrode, and havingan opening exposing the second end portion and the second reflectionelectrode to the outside; and a second contact electrode on theinsulating layer and connected to the second reflection electrode andthe second end portion through the opening, and any one of the first andsecond reflection electrodes is connected to the thin film transistor.14. The display device of claim 13, wherein any one of the first andsecond reflection electrodes is on the partition wall.
 15. The displaydevice of claim 14, wherein the first and second reflection electrodesand the partition wall include different materials.
 16. The displaydevice of claim 15, wherein the partition wall includes an insulatingmaterial and the first and second reflection electrodes include aconductive material.
 17. The display device of claim 13, wherein whenviewed on a plane, the first contact electrode overlaps the firstreflection electrode, and the second contact electrode overlaps thesecond reflection electrode.
 18. The display device of claim 13, whereineach of the plurality of light emitting elements is a light emittingdiode shaped like a cylinder or a polyprism having a micro scale or anano scale.
 19. The display device of claim 13, wherein any one of thefirst and second contact electrodes includes a conductive material, ofwhich a work function is less than 4.1 eV, and the other of the firstand second contact electrodes includes a conductive material, of which awork function is larger than 7.5 eV.
 20. The display device of claim 13,wherein each of the first and second reflection electrodes is on thepartition wall.